On Mon, 16 Nov 2009 10:51:48 +0900 Tejun Heo <tj@xxxxxxxxxx> wrote: > 11/16/2009 03:33 AM, Arjan van de Ven wrote: > >> Enabling DIPM means that the drive will be in charge of > >> transitioning the link into powersave modes, so if sampling > >> SStatus is necessary to determine how much time the link spends in > >> powersave mode. > > > > do we get a link interrupt when the state changes? > > (with ALPM we do.. optionally.. which is where the flag comes in) > > It will depend on the controller I suppose but we can always poll. > I appreciate the possibility but at this point... it's only that. To be honest, nothing in the last 2 or 3 years has moved forward in this area that I can see, even DIPM seems to be AHCI only based on a grep. If a polling controller comes forward it's going to need a whole bunch of infrastructure; a sysfs flag to control the polling and its frequency being the least of the technical problems. Moving the base accounting logic to libata wasn't too painful (see the patch); moving this very driver specific logic gets a much more intertwigned relationship that at this point in time is just overkill. If someone comes around with a driver that also need it, can we just please resolve it at that time? -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
